I initially built a 9038/mercury and recently have been comparing to a 9028/legato/mercury. When I swap the 9038 with the 9028, using the exact same set-up (same power supplies, same mercury, same voltage regulators and voltages) the 9028 is sounding more balanced with better bass. The 9038/mercury sounds thin and I can't figure out what's going on.

There were earlier iterations of the 9038 build where bass sounded better, but along the way it started to sound thin. Being able to compare directly against the 9028 was helpful to confirm something does seem to be going on, but I can't figure out what. All else being equal, the only thing I can think of is that my current digital playback settings through the 9038 is somehow hampered in a way the 9028 isn't. DSD does make the 9038 sound better (but the 9028 sounds better too) and improves the low end. The best I can describe it is that it sounds like the resolution is there, but the sound just isn't "right." Moving to the 9028 sounds a bit more compressed, but the sound is more musical, more full sounding and balanced without the harshness.

I don't think this is simply how the 9038 sound, but rather that something is going on. I'd be interested in anyone else's thoughts that has experience with both.